The present invention relates to testing and simulation of a microprocessor chip. In particular, the present invention relates to an emulation package for an emulation chip.
A modern integrated circuit board typically includes multiple microprocessor chips. An example of an integrated circuit (IC) board 100 with a microprocessor chip 102 is shown in FIG. 1. Microprocessor chip 102 actually represents a microprocessor chip contained in an electronic package. An example of such a chip is a commercial microprocessor chip manufactured by Siemens.
Once the microprocessor chip 102 is placed on the IC board 100, it is typically tested to ensure proper performance. However, since the actual chip is typically contained in an electronic package, the microprocessor chip 102 is generally inaccessible. In order to analyze the performance of a chip 102 embedded in an IC board 100, an xe2x80x9cin-circuit emulatorxe2x80x9d is commonly used to emulate the processes of the target chip 102. An xe2x80x9cin-circuit emulatorxe2x80x9d is typically a box of hardware (or plug-in card) which emulates the microprocessor in a target system via a cable connection. The in-circuit emulator can execute code in the target system""s memory (typically erasable programmable read only memory (EPROM) or random access memory (RAM)), or it can execute code which has been downloaded to the emulator.
The emulator may monitor everything that is happening in the microprocessor, such as monitoring the contents of registers. For example, the emulator may be asked to check a write cycle to an EPROM""s area of memory space to provide a listing of the last one hundred instructions executed before a write-to-EPROM error.
FIG. 2 shows a block diagram of an example of an in-circuit emulator. FIG. 2 includes an IC board 100 coupled with a connector board 202. IC board 100 would be coupled to the target microprocessor chip under normal conditions. However, during testing and emulation, IC board 100 may be coupled with connector board 202 via a connector 208. The purpose of connector board 202 is to facilitate a connection with an in-circuit emulator 200.
In-circuit emulator 200 is shown to include connectors 206 and an emulator chip 204. In-circuit emulator 200 may be any in-circuit emulator, such as those manufactured by HiTex or Nohau. Emulation chip 204 typically has the same interface with the environment as the target microprocessor chip (102 of FIG. 1) in order to emulate the same processes and functions that target chip 102 would perform. However, emulator chip 204 also typically facilitates extra signals which may be used to trace control and trace problems within emulator chip 204. For example, a target microprocessor chip 102 may contain 100 to 200 connector pins for electronic signals, while emulator chip 204 designed to emulate target chip 102 may include more than 400 connector pins. In order to accommodate the extra connector pins for the signals used during testing, emulator chip 204 is typically very large. The need to accommodate the extra connector pins requires that emulator chip 204 be typically encased in a different sized and shaped electronic package than the target chip""s package in order to accommodate the extra connectors.
Since emulator chip 204 is encased in a different package than target chip 102, it is common for the two electronic packages to have an incompatible packaging footprint which typically makes it difficult, if not impossible, to directly place the emulator chip 204 onto IC board 100. A packaging footprint may include factors such as the number of connector pins, the length of the connector pins, the geometry of the package, and distance between the connector pins (pitch). Since emulator chip 204 is typically not directly placed onto IC board 100, long connector lines are typically required to connect emulator chip 204 with IC board 100. An example of the connector line length is approximately five inches. These long lines undesirably slow down the speed of the system.
Another disadvantage of using conventional emulation chip packages is that only a very small number of emulation packages are typically produced. Accordingly, the manufacturing of specially designed emulation packages are typically very expensive since the cost of manufacturing is not absorbed in the volume of produced emulation packages.
It would be desirable to have an emulation chip package which can be manufactured at a reasonable cost. It would also be desirable to have an emulation chip package which has the same or compatible footprint as the target chip such that the emulation chip can be directly coupled to the IC board in place of the target chip. Additionally, it would be desirable to minimize the length of the connectors between the IC board and the emulation chip. The present invention addresses such needs.
The present invention relates to electronic packaging and a method for manufacturing the same. According to an embodiment of the present invention, an emulator chip package is designed and assembled such that a bottom portion of the emulator chip package is approximately the same electronic package used to package the target chip. Additionally, a top portion of the emulator chip package is approximately a slightly modified version of the same type of package used to package the target chip. According to an embodiment of the present invention, the top portion of the emulator chip package is attached to the bottom portion of the emulator chip package. Connector pins of the top portion of the package preferably leads up, while the connector pins of the bottom portion of the package preferably leads down.
The emulator chip package according to an embodiment of the present invention has approximately the same or compatible footprint as the package of the target chip and thus may directly replace the target chip on the IC board. Additionally, with the addition of the top portion of the emulator chip package, the emulator chip package will have double the number of connector pins as the target chip package. The extra connector pins of the emulator chip package may facilitate the extra signals required for testing and emulation. Alternatively, the extra pins may be used to connect to a printed circuit board which can facilitate extra signals required for emulation.
An electronic package for an emulation chip is presented according to an embodiment of the present invention. The electronic package comprises a first portion of the electronic package, wherein the first portion may be directly coupled with an integrated circuit board. A first set of contacts is coupled with the first portion, the first set of contacts being configured to conduct electrical signals. A second portion of the electronic package is also included, the second portion being coupled to the first portion. A second set of contacts is coupled with the second portion, the second set of contacts being configured to conduct electrical signals.
In another aspect of the present invention, a method for manufacturing an electronic package according to an embodiment of the present invention is presented. The method comprising providing a first electronic package, providing a second electronic package, and attaching the first and second electronic packages together to result in a resulting electronic package.